Hello, I own a 2003 Ford Ranger Edge (The one with the 2 suicide doors). With all that room in the back I plan on putting a slim subwoofer (Kicker L7T) in the back behind the passenger seat. I need help finding out where to route my power wire for the amplifier. I see other threads about this, but some people saying run it under the car, on the passenger side, an "open gromet" on the drivers side, but I look around and have no luck trying to find a suitable place for the wire. I plan on running 4 gauge wire, so am I best off running it through the steering column? Thanks.

 

Welcome to the forum

Throttle cable or automatic shift cable can work as well, or E-brake cable

4ga????

Its better "safe than sorry" but you aren't wiring a starter motor or winch

Audio "watts" are not the same as 12volt power watts/amps
at 12volt 10 gauge can do 30amps at 9ft, 8ga 30amps at 14ft

You might need maybe 8ft of wire

 

Ron- most of the amplifier installation kits you can find these days is some crappy Copper Clad Aluminum (CCA) so they up size the wire big time to help accommodate for the fact it isn't as conductive. Plus the larger wire can help with keeping the amp from being starved for juice after a hard it or a very powerful note.

anyways, when I was running my smaller system, I took the wire through a grommet up high behind the dash that had a good sized empty spot. I just made my own hole and pulled the wire through letting it make the hole as it went.

when I up sized everything to 1/0 OFC (oxygen free copper) cable, I ran it under the truck inside the frame rail and then brought it through the floor behind the seats. There are 2 existing body plugs under the carpet behind the front seats. You should be able to see them from under the truck. Also, when you do your ground wire, the easiest place to go is one of the seat bolts. Just get a ring terminal big enough and put it under the bolt. It'll work very well.

 

I don't think the wire size would "starve" the amplifier of power, that would be an alternator issue, and you would install Capacitors, at the amplifier, to store extra AMPs so alternator doesn't get spiking high AMP demand on "low notes"

Nothing at all wrong with running larger wire, not saying that at all, but in car audio the wire size is usually not the issue if lights dim with sub use, lol

 

I remember that my dash lights still dim in my Ranger if I really push my system. And that's with a 250amp alternator with 1/0 OFC run straight to the main group 65 agm battery through a 250a fuse and then connected to 2 group H8 AGM batteries with 1/0 OFC and then 1/0 ofc run from those batteries into the cab to a distribution block where it hits both amps. Ground wires are also all 1/0 OFC as well. From what I can remember from researching when I built my system, a capacitor is only really good for a momentary draw. Sustained draw doesn't do any good.

and it even does this with the engine revved to 2k.
so what do you think the issue would be for me?

 

Batteries are 12.8volts brand new, but at 3 years they are 12.5volts, a battery is only there to start the engine, after engine is running lowest voltage in the system should be 13.5volts from alternator

Your lights dim because alternator can not maintain the AMPs(13.5-14.5volts) required or voltage regulator can't respond fast enough to the spike in Amp draw from a subwoofer, which is where the capacitors come in, the momentary spikes that happen are too fast for a voltage regulator to respond to
Capacitors "store amps" at say 13.5volts then if voltage drops to 13.4volts they start to release amps to maintain the 13.5volts instantly, they are used to maintain whatever voltage is on the line they are hooked to
They can give a voltage regulator enough time to respond to an extra draw of amps, but you would need a few of them on the sub amps

So voltage drops to battery levels which you see as lights dimming because they were at 13.5-14.5volts and drop to 12.5volts

You could run your sound system off the 2 batteries at 12volts isolated from the alternator system except to charge the batteries, as needed, so no dimming lights, vehicle system would be as normal, alternator and one battery for starting, you would add a relay to charge the 2 batteries as needed, and they could be charging all the time until you wanted max sound levels, then you could switch off relay and just run the sound system on battery power

I would imagine the system works fine engine off, the alternator and voltage regulator are the issue, they run at a higher voltage to "maintain" battery charge when engine is running, and are not made for fast changes in a sound systems power draw


Voltage regulators work on "push back" AKA electromotive force
Vehicle regulators are set for about 13.5volts and 14.9v maximum
After startup the battery is drained a bit, so regulator will not have much pushback so will push out 14+volts
As battery recharges it starts to "pushback" voltage, so regulator starts to reduce voltage/amps
If you turn on the headlights or turn blower/fan to HIGH pushback DROPS so regulator adds more amps until it gets "pushback" again
This is all pretty slow in electrical terms so would never keep up with fast changes in pushback

 

Interesting read Ron. That makes sense. At one point, I did have the secondary batteries run through a 500a battery isolator that way I could Jumpstart the truck from sitting in the driver seat, however, I kept having issues with corrosion inside them since it was in the bed, so I just deleted it.